C-1 third arm support bracket question

[Tim M.]

I am thinking of rebuilding the front suspension on my 1954 Corvette. I noticed that the 3rd arm support bracket has been welded. How big a deal is this? Should I automatically replace it or consider the weld reinforcement insurance against a future failure. Will all C1 Corvette 3rd arms and 3rd arm support brackets interchange with each other? The 3rd arm support bracket is #3742688. I have not checked the part # on the 3rd arm yet. Thanks.

[Tony R.]

Re: C-1 third arm support bracket question

I think most of the time when they are repaired it is because someone broke them by using them as a jack lift point. They look inviting when peering under the front of the car. Not sure about the interchangeability for various years.

[Mike M.]

Re: C-1 third arm support bracket question

welded support dangerous at any speed. replace it. mike mccagh

[David B.]

Re: C-1 third arm support bracket question

3742688 was designed for use along with aluminum shims. It was used starting in '57. 53-55 3rd arm bracket is cast/part number 3706024. Check what you have on your car. 3742688 will work on all C1s but should be installed with shims as engineered.

[Dan D.]

Re: C-1 third arm support bracket question

Tim, the shims to increase castor did not appear in production until mid 1956. This change also added spacers on the third are mounting holes to accommodate the increased angle, so your 54 should have the 024 bracket, no shims and no spacers. That is providing it is of original configuration.

I agree completely with Mike, do not use a welded support arm, or anything 'welded' in the steering assembly.

These front ends are middle ages pieces of work for sure, but they do work well as long as everything is tight. And all the pivot joints are metal on metal, so they do wear, especially if they have not been well greased in the past 68 years.

All the parts needed to rebuild these front ends are available from our suppliers; Corvette Central and Paragon in particular. But they are difficult to rebuild; they require human 'feel' in some areas for setting clearances, and much expertise in general. If you are attempting to do this yourself, that is possible, but I strongly recommend you reading a white paper that Tom Parsons wrote some years ago. It is available on NCRS and the internet. You should make contact with Tom; he is very cooperative and he is the resident expert on these old front ends, and the steering boxes too. He posts often on this forum, and a 'thread search' should provide you with much info.

Let us know how you make out.

Dannnn

[Leo G.]

Re: C-1 third arm support bracket question

If it was welded properly ( preheat postheat, proper rod, correct process and heat, I wold use it. However without knowing any of the information I would replace. Too much riding on that component to chance failure. JMHO

Drive safe
Leo

[Dan D.]

Re: C-1 third arm support bracket question

Tim, the shims to increase castor did not appear in production until mid 1956. This change also added spacers on the third are mounting holes to accommodate the increased angle, so your 54 should have the 024 bracket, no shims and no spacers. That is providing it is of original configuration.

I agree completely with Mike, do not use a welded support arm, or anything 'welded' in the steering assembly.

These front ends are middle ages pieces of work for sure, but they do work well as long as everything is tight. And all the pivot joints are metal on metal, so they do wear, especially if they have not been well greased in the past 68 years.

All the parts needed to rebuild these front ends are available from our suppliers; Corvette Central and Paragon in particular. But they are difficult to rebuild; they require human 'feel' in some areas for setting clearances, and much expertise in general. If you are attempting to do this yourself, that is possible, but I strongly recommend you reading a white paper that Tom Parsons wrote some years ago. It is available on NCRS and the internet. You should make contact with Tom; he is very cooperative and he is the resident expert on these old front ends, and the steering boxes too. He posts often on this forum, and a 'thread search' should provide you with much info.

Let us know how you make out.

Dannnn

Let me clarify something I wrote. Although this change occurred in 1956, it probably was not incorporated in production until early 1957.

If you have a 688 bracket, then you want the shims, and no spacers. You will have 2* of caster.

I show the earlier bracket as 3727511. I'm not sure what 3706024 is.

If you have a 511, and you are not using shims, then don't use any spacers (which really are thick washers). You will have 1* of caster. (original configuration).

If you are using the 511 with shims, then use the spacers. You will then have 2* of caster.

Dannn

[Leo G.]

Re: C-1 third arm support bracket question

If it was welded properly ( preheat postheat, proper rod, correct process and heat, I wold use it. However without knowing any of the information I would replace. Too much riding on that component to chance failure. JMHO

Drive safe
Leo

[David B.]

Re: C-1 third arm support bracket question

For educational reference: Grp. 6.186

3706024 53-55 Corv. replaced 4-1-56 --use 3725711 56 Corv. replaced 8-1-57--- use 3742688 57 Corv.

[Tim M.]

Re: C-1 third arm support bracket question

It looks like the third arm is #3700023. This will work with all third arm support brackets, right?